Conventionally, in Japanese Patent Laid-open Publication No. H11-46427, as shown in FIG. 5A, a grommet 100 is attached to a wire harness W/H routed from an engine compartment X to a cabin interior Y of an automobile. The grommet 100 is then mounted to a through-hole H in a panel P dividing the engine compartment from the cabin interior to prevent water infiltration into the cabin interior. Also, in order to reduce or prevent transmission of noise from the engine compartment X to the cabin interior Y, there is a case where a silencer 110 is attached to the forefront of the grommet 100 positioned on the cabin interior Y side.
As shown in FIG. 5B, the silencer 110 has a double-layered configuration to which a vinyl chloride surface skin 110b is bonded to a surface of a sound absorbing material 110a configured with a cylindrical foam body. The sound absorbing material 110a and the surface skin 110b are provided with a straight-line slit 110d running from the outer periphery to a central hole 110c. Further, the center of the surface skin 110b is provided with a plurality of notches in a radial fashion forming a plurality of tongue tabs 110e for attachment to the wire harness. The tongue tabs 110e are fixated to the wire harness by winding a tape T therearound.
The attachment of the silencer 110 to the wire harness W/H takes place after the grommet 100 is mounted to the wire harness W/H. The silencer 110 is attached to the wire harness W/H in a state where an end face of the sound absorbing material 110a in the silencer 110 directly contacts an end face 100e of the grommet 100 without gaps. That is, after the wire harness W/H has been inserted into the central hole 110c by opening the slit 110d of the silencer 110, the attachment tongue tabs 110e formed by cuts from the center of the surface skin 110b are fixated to the wire harness W/H by winding the tape T therearound.
In this way, once the wire harness W/H to which the grommet 100 and the silencer 110 have been mounted has been passed through the through-hole H in the divider panel P from the engine compartment X to the cabin interior Y, by pulling the wire harness W/H back toward the engine compartment X side, the grommet 100 is engaged with the through-hole H in the divider panel P. In this state, a surface skin 150a of a silencer 150 configured with urethane and glued to a cabin interior Y side of the divider panel P contacts a surface skin 110b of the silencer 110, removing any gaps, and insulates the sound of noise from the engine compartment X.